1. Field of the Invention
The present invention generally relates to a motion detection apparatus and method, and more particularly to a motion detection apparatus and method capable of detecting motion regions having motion and still regions having no motion.
2. Description of the Related Art
There is a known interlaced scan method and a progressive scan method as scan methods in image display apparatuses. The interlaced scan method is used for general television (TV), and refers to the method in which when displaying one image, the image is displayed on screen by dividing the image frame into two fields and alternately transmitting one of them and then the other. On the other hand, the progressive scan method is used for a computer monitor, digital television and the like, and refers to the method in which the full frames are displayed in one frame unit at a time as a moving picture (e.g., a film) is projected on the screen.
With increasing necessity of data exchange between apparatuses using different scan methods, because of the increasing image display apparatuses using the progressive scan method, various interpolation methods are needed for converting the interlaced scan method into the progressive scan method.
As general interpolation methods, there is an intra-field interpolation method forming a new field by inserting a given data into the region between two lines of the current field, the given data being obtained by dividing the data of the two lines by 2, and an inter-field interpolation method without the compensation for motion by forming one frame, using the lines corresponding to the fields immediately before and after the current field, between the lines of the current field.
The intra-field interpolation method is suited for interpolating the motion region having motion, and the inter-field interpolation method is suited for interpolating the still region having no motion. However, since it is common to have the motion regions and the still regions in the scene, it is effective to interchangeably use the intra-field interpolation method and the inter-field interpolation method for improving the image quality after the interpolation. In this case, by calculating a proper mixing factor (α) based on information detecting the motion region and the still region in the scene and using the mixing factor, it is possible to interchangeably use the intra-field interpolation method and the inter-field interpolation method.
Thus, to obtain the improved image quality by the intra-field and inter-field interpolations, it is primarily required to correctly detect the motion region and the still region in the field to be presently interpolated. To this end, based upon the previous field and the next field immediately before and after the current field to be interpolated, a method is generally used for detecting the motion region and the still region in the field to be presently interpolated by using the difference of the luminance values between pixels at corresponding locations.
However, according to the above-described detection method, due to a very quick motion in the scene, there often occurs a problem that the process may not correctly detect the motion region and the still region only by the luminous value comparing with the preceding field and the succeeding field. As a consequence, a spurious still region may occur, the spurious still region referring to a region that is substantially the motion region, but is erroneously detected as the still region. Therefore, to improve the image quality after the interpolation, a method is needed for correctly detecting the motion region without the spurious still region occurrence.
As the prior art related to such a method, there is a method for detecting the motion region using pixel values and a brightness profiles pattern difference (BPPD) disclosed in Korean Patent Laid-open No. 2001-2659. Also, Korean Patent Laid-open No. 2001-90568 discloses another method in which the motion region is detected using the motion metric by combination of the prescribed pixel luminance values.
However, according to the above-described disclosed methods, the circuit implementation for detecting the motion region is somewhat complex, and it is expected that the processing speed is accordingly not high due to the complexity of the circuit. Thus, a new apparatus and method is needed for quickly detecting the motion region and the still region with easy implementation (i.e., by detecting the motion region with a more simple construction than the existing methods).